gsub X Lua 3.1

[tomas@... (Tomas Guisasola Gorham)]

	Hi,

	anticipating problems with the incompatibility of gsub between
Lua 3.1 and Lua 3.0, I made a Gsub function (below) which intends to do
the same job as the obsolete one.  Maybe it will be useful to some of
you (and maybe you can test it too :-) ).

	Tomas

======================================================================
function Gsub (str, pat, repl, table, n)
   if not table then
      return gsub (str, pat, repl)      
   elseif type (table) ~= "table" then
      return gsub (str, pat, repl, table)
   else
      local t = { n=0 }
      local f = function (...)
         %t.n = %t.n + 1
         local i = 1
         local newargs = { %table, %t.n }
         while i <= arg.n do
            newargs[i+2] = arg[i] 
            i = i+1
         end
         newargs.n = i + 2 - 1
         return call (%repl, newargs)
      end
      if n then
         return gsub (str, pat, f, n)
      else
         return gsub (str, pat, f)
      end
   end   
end